//========================================================================
// GLFW - An OpenGL library
// Platform:    Cocoa/NSOpenGL
// API Version: 3.0
// WWW:         http://www.glfw.org/
//------------------------------------------------------------------------
// Copyright (c) 2009-2010 Camilla Berglund <elmindreda@elmindreda.org>
//
// This software is provided 'as-is', without any express or implied
// warranty. In no event will the authors be held liable for any damages
// arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented; you must not
//    claim that you wrote the original software. If you use this software
//    in a product, an acknowledgment in the product documentation would
//    be appreciated but is not required.
//
// 2. Altered source versions must be plainly marked as such, and must not
//    be misrepresented as being the original software.
//
// 3. This notice may not be removed or altered from any source
//    distribution.
//
//========================================================================

#include "internal.h"


//========================================================================
// Check whether the display mode should be included in enumeration
//========================================================================

static GLboolean modeIsGood(CGDisplayModeRef mode)
{
    uint32_t flags = CGDisplayModeGetIOFlags(mode);
    if (!(flags & kDisplayModeValidFlag) || !(flags & kDisplayModeSafeFlag))
        return GL_FALSE;

    if (flags & kDisplayModeInterlacedFlag)
        return GL_FALSE;

    if (flags & kDisplayModeTelevisionFlag)
        return GL_FALSE;

    if (flags & kDisplayModeStretchedFlag)
        return GL_FALSE;

    CFStringRef format = CGDisplayModeCopyPixelEncoding(mode);
    if (CFStringCompare(format, CFSTR(IO16BitDirectPixels), 0) &&
        CFStringCompare(format, CFSTR(IO32BitDirectPixels), 0))
    {
        CFRelease(format);
        return GL_FALSE;
    }

    CFRelease(format);
    return GL_TRUE;
}

//========================================================================
// Convert Core Graphics display mode to GLFW video mode
//========================================================================

static GLFWvidmode vidmodeFromCGDisplayMode(CGDisplayModeRef mode)
{
    GLFWvidmode result;
    result.width = CGDisplayModeGetWidth(mode);
    result.height = CGDisplayModeGetHeight(mode);

    CFStringRef format = CGDisplayModeCopyPixelEncoding(mode);

    if (CFStringCompare(format, CFSTR(IO16BitDirectPixels), 0) == 0)
    {
        result.redBits = 5;
        result.greenBits = 5;
        result.blueBits = 5;
    }
    else
    {
        result.redBits = 8;
        result.greenBits = 8;
        result.blueBits = 8;
    }

    CFRelease(format);
    return result;
}


//////////////////////////////////////////////////////////////////////////
//////                       GLFW platform API                      //////
//////////////////////////////////////////////////////////////////////////

//========================================================================
// Get a list of available video modes
//========================================================================

int _glfwPlatformGetVideoModes(GLFWvidmode* list, int maxcount)
{
    CGDisplayModeRef mode;
    CFArrayRef modes;
    CFIndex count, i;
    int stored = 0;

    modes = CGDisplayCopyAllDisplayModes(CGMainDisplayID(), NULL);
    count = CFArrayGetCount(modes);

    for (i = 0;  i < count && stored < maxcount;  i++)
    {
        mode = (CGDisplayModeRef) CFArrayGetValueAtIndex(modes, i);
        if (modeIsGood(mode))
            list[stored++] = vidmodeFromCGDisplayMode(mode);
    }

    CFRelease(modes);
    return stored;
}

//========================================================================
// Get the desktop video mode
//========================================================================

void _glfwPlatformGetDesktopMode(GLFWvidmode *mode)
{
    *mode = vidmodeFromCGDisplayMode(_glfwLibrary.NS.desktopMode);
}